Method for rejuvenating used self locking nuts



Nov. 27, 1962 B. .1. HANSEN METHOD FOR REJUVENATING USED SELF LOCKINGNUTS Filed Sept. 9, 1957 IN V EN TOR.

BOBBY J; HANSEN 3,065,529 Patented Nov. 27, 1962 Fr ce 3,065,529 METHODFOR REJUVENATWG USED SELF LOCKING NUTS Bobby .I. Hansen, Box 114,Snrfside Colony, Calif. Filed Sept. 9, 1957, Ser. No. 682,824 1 Claim.(Cl. 29-401) This invention relates to new and improved apparatus andmethod for rejuvenating used, self-locking nuts.

A large number of different types of self-locking nuts have beendeveloped in the past. At the present time, self-locking nuts which arebuilt so as to include a center-nut-like portion having a threadedopening extending therethrough, a flange extending from one side of thecenter nut-like portion around the opening, and an elastomeric memberheld around this opening under compression by this flange, are Widelyused for a variety of purposes. These nuts are considered very eflicientas initlally used, and appear to be replacing various conventional andolder types of self-locking nuts for a number of different purposes.

Self-locking nuts of the type described in the preceding paragraph,however, suffer from certain inherent disadvantages. After these nutshave been used for a long period, the elastomeric members employed inthem tend to fail to exert a desired locking action against a threadedmember such as, for example, a common bolt. Although a number oftheories have been advanced as to why these elastomeric members fail toexercise their desired function after a prolonged period, it is believedthat no one completely has the answer to this problem.

It can be theorized that the elastomeric members used in self-lockingnuts of the type indicated in the preceding discussion, fail to exercisetheir desired function after prolonged periods due to the surface areasof these elastomeric members which engage threaded members failing ordeteriorating because of chemical reasons, or because of mechanicaldisruption through repeated engagement with threaded surfaces. Both ofthese theories are at least theoretically acceptable. It is well knownthat elastomeric materials such as, for example, various rubbercompositions, will tend to deteriorate at their surfaces, so as to notretain their inherent initial properties. It is also Well known thatthreads will tend to cut into various elastomeric materials to varyingextents. Indeed, many types of constructions are based upon the abilityof threads to be cut into certain elastomeric materials. It is alsopossible that self-locking nuts of the type indicated may fail toexercise a desired holding action after prolonged use because of theflanges used on these nuts to hold these elastomeric members yielding tosome extent.

An object of the present invention is to provide a new and improvedmethod for treating used self-locking nuts of the type described so asto return these nuts to subtantially their initial effectiveness.

Because of the nature of this invention, it is not considered necessaryor expedient to set forth in further detail a long list of variousobjects and advantages of the invention. Such other objects andadvantages of the invention will be fully apparent to those skilled inthe art to which this invention pertains from a detailed considerationof the remainder of this description, including the appended claims andthe accompanying drawing in which:

FIG. 1 is a side elevational view of a used, self-locking nut capable ofbeing rejuvenated in accordance With this invention;

FIG. 2 is a cross-sectional view taken at line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view, similar to FIG. 2, of

self-locking nut shown in the preceding figures which has been treatedaccording to this invention;

FIG. 4 is a perspective view of a die used in accordance with thisinvention in rejuvenating used, self-locking nuts; and

FIG. 5 is a diagrammatic view showing the use of this die, this figureshowing the die in section along line 55 of FIG. 4.

In all figures of the drawing like numerals are used to designate likeparts wherever convenient for purposes of illustration and explanation.It is to be understood that this invention is capable of being used withself-locking nuts having a diiferent appearance than the appearance ofthe self-locking nuts illustrated. Similarly, it is to be understoodthat the basic principles of this invention can be employed withdifferently appearing dies which are specifically designed so as to beused with various types of self-locking nuts.

As an aid to understanding this invention it may be stated that itconcerns the rejuvenation of used, self-locking nuts, each of which nutsis formed so as to include a center nut-like portion having a threadedopening extending therethrough, a flange extending from one side of thecenter nut-like portion around the opening, and a ring-like elastomericmember held around the opening on this side by this flange against thecenter nut-like portion so as to be held under compression. Inaccordance with the method of this invention, such nuts are treated sothat the flanges employed in them are bent toward the center nut-likeportion around the opening in order to change the compression on theseelastomeric members, and so as to extend these members toward thecenters of these openings so that these elastomeric members mayefficiently serve the purpose of holding the complete selflocking nutsin place against threaded members passing through these nuts. Theapparatus of this invention involves die means as Will hereinafter bedescribed for use in bending such flanges.

In FIG. 1 of the drawing there is shown a used, selflocking nut 10 ofthe type which is specifically adapted to be treated in accordance withthis disclosure. This nut 10 includes a center nut-like portion 12having a threaded opening 14 extending therethrough. On a side 16 ofthis center nut-like portion 12 there extends a ring-like curved flange18 which serves to define between this flange and the side 16 of thenut-like portion 12 a ring-like internal cavity 2t) within which aring-like elas tomeric member 22 is held under compression. Thiselastomeric member 22 may be formed out of a wide variety of materials,such as, for example, various rubber compositions, various polyurthaneresins, polychloroprene or the like.

In a used, self-locking nut, such as the self-locking nut 10, as shownin F168. 1 and 2 of the drawing, the elastomeric member possesses asurface 2-4 constituting an extension of the opening 14, and thissurface 24 is of a generally enlarged variety so that the elastomericmember 22 cannot resiliently hold a bolt or the like extending throughthe opening 14. Normally the elastomeric member 22 is held undercompression through the use of the flange 18. If desired, this flange 18may be provided with slots 26, so as to subdivide it into a plurality offingers, each of which fingers engages the elastomeric member 22.

In order to rejuvenate this self-locking nut 10, it is considerednecessary to bend the flange 18 so that this flange 18 exertscompression upon the elastomeric member 22 in order to force the surface24 of this elastomeric member to a configuration, such as indicated inFIG. 3 of the drawing. As previously indicated in this figure there isshown in cross-sectional view the self-locking nut 10 treated or afterbeing rejuvenated in accordance least one opening or cavity 32, whichhas a top portion 34 which is shaped to the exterior shape of thenut-like portion 12 of the self-locking nut ill), but which is shorterthan this nut 10. This top portion 34 terminates in an internal flange36 whic'h'is adaptedto receive the portion.

of the side 16 of a nut 10 between the flange 1t; and this nut-likeportion lz. The cavity 32 also has a bottom section 38 which correspondsin shape to the shape of i the flange 18 finally desired when theself-locking nut 10 is rejuvenated as shown in FIG. 3., If desired, anynumber of cavities such as cavity 32 may be placed within the die 30. V

In using this die it is located as shown-between a fixed platen 4t? anda movable platen 42 on any sort of a convenient hydraulic press or theequivalent. 'Next, the nut 10 as shown in FIG. 5 is placed Within thedie 30 in .the obvious manner, and the platens 40 and 42 are causedtomove against one another so as to apply forcein a lengthwise directioncorresponding to the direction of the axis of the opening 14in order tocompress this nut and deform the flange 18 the .desired amount, and soas to extend the surface 24 of the elastomeric member 22 being treatedto a necessary extent so that this elastomeric member 22 of the nut 10is capable of holding a threaded" member with the force thatit wasinitially capable of exerting By this type of treatment, the elastomericmembers within self-locking nuts of the type described are not onlypushed slightly toward the centers of openings within these nuts, butthese elastomeric members are deformed slightly from their initialconfigurations so that dilterent portions of these elastomeric membersare, it is theorized, placed so as to be engaged by different portionsof threaded members than previously. Also, by virtue of this process,the elastomeric members 22 tend to be extended within the nuts treatedto a certain extent, and it is believed or theorized that the surfaceportions of these .nuts are moved slightly so that the interior poringthrough said opening so as to lock said threaded memtions of theseelastomeric members which probably are unharmed by oxidation or otherlike aging influences can be eflectively used in exercising a lockingaction.

Because of the nature of this invention and the fact that it is capableof wide modification, it is considered as being limited only by theappended claim forming a part of this disclosure. 7

I claim: 7

A method for rejuvenating a used, self-locking nut, said nut beingformed so as to include a center nut-like portion having a threadedopening extending therethrough, a flange extending from one side of saidcenter nut-like portion around said. opening,'and an elastomeric memberheld around said opening on said side by said flange against said centernut like portion under cornpression, said eiastorneric member'having asurface constituting a continuation of said opening, which surface isdesigned to resiliently engage a threaded member extendber in place,said used self-locking nut being-characterizedby said elastomeric memberno longer presenting an eflective surface for engaging and holding athreaded member extending through said opening, which method comprises:applying force to said flange around said opening so as to bend saidflange toward said centernutlike portion aroundsaid opening, saidbending of said flange serving to change the compression on saidelastomeric member so as to deform said elastomeric member slightly insuch a manner as to extend said elastomeric member toward the centerofsaid opening so that said surface of said elastomeric member is capableof efiiciently holding a threaded member extending through said opening.

References Cited in the file'of this patent UNITED STATES PATENTS1,879,250 Hopkins Sept. 27, 1932 2,070,032 Swanstrom Feb. 9, 19372,337,797 Brackett Dec. 28, 1943 2,355,871 Kraft Aug. 15, 1944 2,421,905Perry June 10, 1947 2,429,832 Luce Oct. 28, 1947 2,487,129 Hallock Nov.8, 1949 2,810,312 Mueller n Oct. 22, 1957

